The contamination due to extensive fungal growth of an excess of 10,000 items of previouslyconserved archaeological leather initiated a research project to investigate, evaluate, and compare methods of reconservation. Previous conservation mediums were based on British Museum Leather Dressing or lanolin. Solvent extractions of the old mediums with petroleum spirit 60° to 80°C, white spirit, and Genklene (stabilized 1,1,1-trichloroethane) were examined. Impregnations of Genklene-extracted leather with polyethylene-glycol (PEG) 400, glycerol, sorbitol, and PEG/glycerol combinations in ethanol were investigated. The quantity of finds requiring treatment imposed restrictions on the method of treatment selected as well as its execution. The affected leather was mechanically cleaned, extracted with Genklene, and impregnated with 10%/ 10% PEG/glycerol v/v/v in ethanol. The treatment was carried out on a large scale with consistent and acceptable results which continue to be monitored on a periodic basis. See also AATA 21-1193.